Lift mechanism or the like



Oct. 17, 1961 J. E. CLARKE LIFT MECHANISM OR THE LIKE Filed June 10, 1959 uw Nm. uw .W QN mw El* T.m LM 1. im@ ,r mw QN v @bm wm. ww. f TS L E WN ml J .QN c Q Q J N j 3,004,272 LIFT MECHANISM R THE LIKE .lesse E, Clarke, Hinsdale, lll., assigner to Autoqup Corporation, Chicagm Ill., a corporation of Illinois Filed June 10, 1959, Ser. No. 819,288 3 Claims. (Cl. `11i-42) This invention relates to lift mechanism or the like, in this instance illustrated as applied toy a transfer bridge for providing a passageway for cross traiiic over a depressed railroad track, for example, in the interior of an industrial plant building or the like.

Heretofore objections have been encountered in the construction and operation of such transfer bridges due to difficulties in installation and operation arising from complexities of construction and uncertainties of safe,

level passage.

The present invention aims to provide a device of this class that is markedly simple in structure and operation and whereby the load is supported at four points without the necessity for complex leveling expedients and whereby enhanced rigidity is afforded with a minimum of structural parts and without the necessity of providing excavations or underground connections.

The invention contemplates a pair of relatively reactionary elements, a leg pivoted at one end to one element and at its other end moving against the other element and a hydraulic jack pivoted to one of the elements and to ,the leg for moving said other end of the leg in movements of the elements toward or away from each other.

An important object of the present invention is the provision of a self-locking function of the mechanism independent of the hydraulic system, at the upper limit of movement, without any extraneous parts.

In a further important aspect, the invention provides individual hydraulic mechanisms at all four corners of the bridge that may be connected with a single small compact power unit that may be placed in any convenient out-of-the-way location and each of which mechanisms when brought to a common predetermined elevated level is automatically mechanically locked in such elevated position, thus assuring complete safety and anti-creep characteristics.

The foregoing and other objects and advantages will be apparent from the following description, taken together with the accompanying drawing showing an illustrative embodiment of the invention and in which drawing- FIGURE 1 is a plan View of a bridge as installed, parts being broken away for explanatory purposes;

FIGURE 2 is a fragmentary cross-section corresponding to the left-hand end of the bridge and its associated structures taken on the line 2--2 of FIG. 1 and when the bridge is in elevated position;

FIGURE 3 is a somewhat similar fragmentary crosssection taken on the line 3-3 of FIG. l and when the bridgeis in lowered or depressed position; and

FlGURE 4 is a fragmentary longitudinal section, taken on the line 4--4 of FIG. 1, the bridge being shown lowered, in full lines, and in raised position as indicated in broken lines; and

FIGURE 5 shows an intermediate position of one of the corner mechanisms.

Referring in detail to the illustrative construction shown in the drawing, numerals 11 and 12 represent factory levels or floors that are separated by a depression 13 in which a railroad track 14 is located, having the usual rails 15 on a road bed 15a. For spanning the gap over the railroad track 14 vbetween the lloors 11 and 12, the bridgeway platform or member 16 is provided that is here representative of a reciprocable member that may Yi .a Stt tent ice be placed in either of two alternative positions, one in which the rail sections 17 carried thereon, in `depressions 18, are brought into register, in one position, here its lowered position, with the rails 15 of the railroad track or, in another position, such as here, with its upper surface 1'9 in horizontal alignment with the factory floors 11 and 12 to provide a passageway thereover on a common level. In its lowered position, as best shown in FIG. 3, and in full lines in FIG. 4, the bridgeway member 16 descends partially into a cavity 20 in the roadway 15a. The bridge member, in such lowered position, is centrally supported by a pair of inverted channel plates 21 laid on upwardly extending projections 22 in the bridge cavity or bed 20. The projections 22 and plates 21 are vertically aligned with the railroad rails 15 and with the bridgeway rail sections 17 and are of a height to cause the bridgeway rail sections and the railway rails 15 to be in horizontal alignment in the lowered position of the bridgeway member, so that railroad cars may travel thereon, such as to bring supplies into the factory or to take out finished products.

In accordance with the present invention, the bridgeway member 16 is hollow on its underside, as best seen in FIG. 4 at 23, and within the space thus enclosed is located, at each corner of the bridgeway member, a hydraulic cylinder 24. A description of the mechanism at one corner will sufl'ice for all four.

The hydraulic cylinder 24 is pivoted, at one end, to the bridgeway member as at 25., and at its other end has projecting therefrom the piston rod 26 which is articulated as at 27 with a support leg 2S, the latter as here shown having an integral laterally offset lug formation 29 with which the piston is connected. Legs 28 move in planes transverse to the track.

The support leg 28 is itself pivoted at one end as at 3i) to the bridgeway member 16 on va lug 31 depending therefrom, apart from and below the pivot 25 of the cylinder to the member. At its other end adjacent which is located the connecting lug 29, the leg 28Vcarries an anti-friction element such as the flanged roller 32 that travels on an inverted V-shaped ridge strip 33 in the bridge bed 20 that serves as a guide for the roller 32 and is within the space defined by the top of the raised projections 22. In the elevated position of the bridgeway member the leg 28 is somewhat vertical and its roller 32 abuts a stop 34 in the bed adjacent -a Wall 35 margining the factory floor 11 or 12 as the case may be. In the lowered position of the bridgeway member the support leg 28 is rotated into horizontal position on the 4guide strip 33, the projection 22 affording room therefor.

Piston rod 26 has thev usual piston 36 Within the cylinder 24 and for -ow of hydraulic iiuid to and from opposite sides of the piston 36 the cylinder has a nipple 37 adjacent its proximal end and another nipple 38 adjacent its distal end.

As a vertical guide means, the bridgeway member 16 carries centrally thereof at each end a roller 39 that travels up andv down on a vertical track 40 ixed on the wall 35 midway between a pair of the cylinders 24.

It will be understood that the nipple 37 may be connected by appropriate piping with a hydraulic pump unit common to all of the cylinders forV forcing oil or other hydraulic uid into each of the cylinders simultaneously and uniformly for lifting the bridgeway member 16. It 4will be further understood that there is normally no load except its own weight on the bridgeway member when it is being lifted so that a common power unit will raise all four corners together.

It is believed unnecessary to here show such a common hydraulic power unit as this may take any form and location as will be readily apparent to workers in the art having the benefit of the present disclosure. It will be 3 further understood that the weight of the bridgeway 16 Vwill cause it to descend as the legs are folded up as next described.

Normally, the bridgeway member 16 will be in Aits uppermost position Vtoppermit travel directly across the railway road bed a.from the factory oor 11 to the factory floor 12 or vice versa, on a common level. Such plant cross traffic is so provided both for pedestrians and for Atransfer trucks, shop mules and the like. Since the rail secti'ons17 carried on the bridgeway member 16 are depressed in the relatively narrow recesses 18 to be flush with the upper surface 19 of the bridgeway member'thereof, these railsections offer no obstacle to such cross traic. The space between the lioorsll and 12 in the area of the bridge is substantially spanned by the bridgeway member 16. When now it is desired to permit a railway train or car to travel along the tracks 15, the bridge is lowered for that purpose. At this time hydraulic iluid is forced under pressure into the distal ends of each of thecylinders 2.4 simultaneously and uniformly, through the nipple 38 for each cylinder. At the same time, hydraulic iluid in the proximal end of the cylinder is permitted to flow out through the nipple 37. This moves the piston 36 toward the proximal end of the cylinder and pulls upwardly on the piston rod 26. This pull upwardly on the piston rod 26 rotates the support leg 28 on its pivot 30 fromthe position shown in FIG. 2 to the position shown in FIG. 3, that is, where the leg 28 is horizontal and lying on the ridge strip 33, the bridgeway member 16 in this lowered position resting on the plates 21 with the rail sections 17 of the bridgeway member in alignment both vertically and horizontally with the rails 15 of the railway, so as to form a continuation of the rails 15.

When the railway train or car has passed by, or has been removed, the bridgeway member 16 may then be again elevated to permit factory cross traffic between the factory oors 11 and 12. ToY accomplish this, hydraulic fluid is permitted to flow out of the nipple 38 at the distal end of each cylinder 24 and is forced under pressure into the proximal end of the cylinder through the nipple 37. vThis forces the piston rod 26 outwardly of the cylinder.

inuence of hydraulic pressure in the distal end of the cylinder will cause the roller28 to move along the ridge strip 33 until it iinally again assumes a position shown in FIG. 3 at which time the leg 28 again lies horizontally along the ridge strip and the cylinder is somewhat horizontal within the interior of the bridgeway member. The pivot point of the cylinder however, is advantageously shown at least slightly above the connection of the piston rod to the leg at 27 so that the next time that pressure is placed outwardly on the piston rod 26 the force will again raise the bridgeway.

The invention is not intended to be limited to details of construction shown for purposes of illustration, and, an exemplary embodiment of the invention having been shown in accordance with the statute, it will be understood that such changes may bemade, including modications or additions, as fall within the scope of the appended claims without departing therefrom.

Since in the lowered position the leg 28 has moved as far downwardly as it can, the force tending to move the piston rod outwardly of the cylinder becomes a force tending to move the cylinder outwardly of the piston, and this force moves the bridgeway member 16 upwardly. With upward movement of the bridge member the roller 32 moves along the guide strip 33 toward the stop 34, the end of the leg 28 which is pivoted to the bridge member at 30 moving upwardly with the bridgeway member, until the leg 28 assumes a vertical position indicated by a vertical line'41 through the pivot 30 (FIG. 2), The parts are desirably so arranged, however, that when the leg member is in this vertical position the roller 32 is not yet in abutment with the stop 34, and continued pressure outwardly on the piston rod 26 forces the roller 32 to a position indicated by the line 42 in which the leg 28 is now past the vertical position, which is to say that all of the legs are spread outwardly at their lower ends. The bridgeway member 16 is then positively and automatically locked in its upper position. Any weight on the bridgeway member willtend to force the rollers 32more firmly against the stops 34 and the rollers will not move away from the stops, regardless of whether or no t hydraulic pressure is maintained in the proximal end of the cylinder.

To move the rollers 32 away from the stops 34, to lower the bridgeway, hydraulic fluid under pressure must be positively introduced into the distal end of the cylinder through the nipple 38. This will momentarily lift the bridgeway member 16 slightly to enable the leg member 28 to move away from the stop-'34 and to assume the vertical position, as shown by the vertical line r41. Continued inward movement of the piston rod 26 under the What is here claimed is:

l. A lift bridge apparatus comprising: a vertically reciprocable bridge; means to guide said bridge for substantially vertical movement between an upper and a lower position; and lift mechanisms positioned at opposite ends of said bridge, each of said mechanisms including a leg pivotally attached at one end thereof to a bottom part of said bridge adjacent the endY of the bridge for movement between a substantially vertical position when said bridge is in the upper position and a substantially horizontal position extending inwardly from said end of the bridge when the bridge is in the lower position, said leg having a roller rotatably attached to the other end thereof and a lug attached adjacent said other end and positioned to project upwardly from the leg when the leg is in the substantially horizontal position, a fixed track below said leg and aligned with the path of said roller during the movement of said leg between said two positions, and fluid operating means having a iluid cylinder body member and a piston rod member extending from said body member, one of said members being pivotally attached to said lug at a point which is above said leg when said leg is in the substantially horizontally position, the other of said members being pivotally attached to said bridge at a point that is approximately directly above the point at which the leg is pivotally attached to said bottom part and is at a higher elevation than is said point when said leg is in the subtsantially horizontal position.

2. The apparatus of claim 1 wherein said leg`4inn moving between said two positions moves across a position at which the point of pivotal attachment of the leg to the bridge and the point of contact of the roller with the track are vertically aligned, whereby the bridge must be raised slightly before it can be lowered, and said apparatus includes a stop means in the path of movement of said leg to prevent said leg from moving beyond said substantially vertical position as the leg moves from the substantially horizontal position to the substantially vertical position.

3. A lift apparatus comprising: a ixed base device, said device having upstanding parts defining a space below their tops; a bridge device having parts resting on said upstanding parts in the lowered position, said bridge device being hollow on its underside and defining a space in the bridge device above said upstanding parts, said bridge device being movable vertically away from said base device; means interconnecting said devices to guide said bridge device during said vertical movement; and at least two spaced lift means to move said bridge device vertically away from said base device, each of said lift means including a irst lug attached to one device and extending into said space in the other device, a leg having one end pivotally attached to said lug at a point with the leg extending generally horizontally in said space in the other device, said leg having a second lug affixed thereto adjacent the other end of the leg with the second lug extending from the leg toward the one device and 5 into said space in the one device, a roller rotatably axed to the other end of the leg, a track aixed to the other device, positioned within said space in the other device and extending from beyond said roller at one end to beyond said point at the other end, and uid operating means having a fluid cylinder body member and a piston rod member extending therefrom, said members being positioned in said space in the one device, one of said members being pivotally attached to said second lug, the other of said members being pivotally attached to said one device at a second point within said space in the one device, in approximately vertical alignment with the first point and spaced a greater vertical dimension from said first point than is the vertical dimension between said rst point and the pivotal connection of the second 15 V2,908,024

6 lug and the one member, whereby as said uid means is actuated to extend the piston rod member out of the body member said leg will be pivoted toward a vertical position between said rst lug and said track to push the bridge device away from the base device.

References Cited in the tile of this patent UNITED STATES PATENTS 1,842,604 Guest Ian. 26, 1932 2,016,468 Wagner Oct. 8, 1935 2,115,328 De Cola Apr. 26, 1938 2,297,992 Swim Oct. 6, 19'42 2,652,783 Skinner Sept. 22, 1953 2,889,565 Harty June 9, 1959 Holleen Oct. 13, 1959 

